Hypnaceae Family

Subclass Bryidae, Green Mosses ( Bryidae )

Order Hypnales ( Hypnales )

Family Hypnaceae ( Hypnaceae )

Leafy aquatic mosses living in springs and fast-flowing rivers with clean, transparent, oxygen-rich water. They attach to the substrate using rhizoids. Stems are heavily branched, leaves are small, and green in various shades of intensity. These mosses are kept in cold-water aquariums, except for tropical species, which grow better in a tropical aquarium.

Genus Vesicularia — Vesicularia.

Java Moss, Singapore Moss — Vesicularia dubyana. “Singapore Moss”.

«1» Synonym: Taxiphyllum barbieri. Widely distributed in the tropics of Southeast Asia. In nature, the plant grows in small, non-drying water bodies with relatively clean water and a weak current, settling at shallow depths near the banks, forming emerald-green dense thickets on flooded stumps, driftwood, stones, and fallen trees. Externally, it is a chaotic, dense intertwining of thin, highly branching stems up to 17 cm long, densely covered with dark green leaves 1-2 mm in size.

In the submerged form, no other organ differences are observed. The plant consists only of stems and leaves. It looks like tangled dark green threads, characterized by extreme shade tolerance and low maintenance. The randomly branching stem of this plant is densely covered with needle-like leaves. Older leaves are dark green, while younger ones are light green. Stems are heavily branched, grow in bunches, form thickets, grow well, and often form large continuous areas of vegetation.

On the lower part of the stem, reddish-brown rhizoids form – thread-like root-like processes. Innumerable rhizoids, through which the moss can attach to almost any surface, are too small to be seen with the naked eye. The most critical phase is the very beginning, when the plant has not yet attached to the substrate. During this period, it places high demands on light and water chemistry. After “rooting”, the plant’s fastidiousness drops significantly. The completion of the initial phase is indicated by the appearance of young, light-green shoots. Java moss grows slowly but steadily throughout the year. If the plant is tied to a piece of driftwood or a stone, its shoots will grow more lushly.

«2» The optimal temperature for keeping this plant ranges from 24 to 28°C. At temperatures below 22°C, its growth practically stops, but the plant retains its appearance for many weeks. Water hardness and active reaction do not matter: Java moss grows satisfactorily in both very soft and hard water with acidic and alkaline reactions. The plant tolerates a very wide range of pH and hardness values perfectly. Java moss is even able to withstand a salinity of 2-3% for a long time. It prefers soft water, around dH 6°, and slightly acidic pH 6.0-6.4. The water must be transparent. In cloudy water, a coating quickly forms on the moss, which not only spoils the appearance of the plant but also disrupts its nutrition. Regular water changes in the aquarium are not mandatory, as the moss develops satisfactorily in old water as well.

The nature of lighting and its intensity do not play a major role. Lighting should not be too strong, but at the same time, daylight hours should not be shorter than 8.5 hours. The duration of daylight depends on the needs of neighboring plants. It is important to prevent algae from multiplying on the delicate branches of the moss. Java moss is undemanding to lighting and can spend months in such dark aquariums where no other plant survives. Under bright lighting, the moss acquires a rich green color, and the threads begin to branch. The thicket becomes dense and has a very attractive appearance. Keeping Java moss does not require any fertilizers, neither in the substrate nor in the water. When placed in favorable conditions — under bright light and in water with a neutral or slightly acidic reaction, preferably enriched with peat extract or tropical blackwater preparation — Java moss grows very quickly and acquires a stunning emerald color.

«5» Although Vesicularia is a common aquatic plant, far from every aquarist can use it correctly for aquarium decoration. If the plant is left undisturbed for a long time, it forms very beautiful openwork thickets. It does not need to be planted in the substrate because it has no roots. Dark green clumps of Java moss can be used as a spawning substrate for aquarium fish. It can grow on decor elements, attaching to them independently. It looks especially good in small aquariums, decorating small decorative elements located in its corners: coconut shells, filter tubes hidden in its thickets, etc. It grows both horizontally and vertically (upwards).

If there is a suitable support nearby, such as a piece of driftwood, a stone, or a porous background, the shoots of this plant easily attach to the porous surface and quickly begin to climb up — closer to the light. If you attach a piece of the plant to a permanent place and do not touch it for several months, you may notice that the growth of the stems occurs differently. First, the stems stretch to the sides and downwards, covering the substrate and ensuring a reliable connection with its surface. Then, having firmly attached, the plant produces a large number of shoots directed horizontally and slightly upwards, so that the entire mass of moss takes the form of multiple layers with an arched arrangement relative to each other. And finally, after the plant has gained a sufficient amount of biomass, the third type of stems begins to grow, directed clearly upwards.

For the plant to truly act as a groundcover and create beautiful clearings with the loose “balls” of its shoots, it is necessary to periodically trim the branches growing upwards and pull apart or stretch overly dense tufts; however, the moss does not grow fast, and such operations will not have to be done often. It is placed in semi-shaded areas with transparent water. But it should be noted that all this is possible only if there is no strong current in the aquarium, no fish disturbing the plant, and the aquarist themselves does not interfere with the natural course of the plant’s development.

It grows best when attached to some kind of base. For this purpose, non-rotting driftwood and stumps can be used. The base is of great importance in the plant’s life, and therefore you should not separate the already attached plant from the substrate. In some cases, this can even lead to the death of the bush. To root it to driftwood, Java moss is carefully laid out on the wood surface in a thin layer and tied with very thin fishing line or cotton thread. In the first few days after fastening to the driftwood, the new moss looks extremely unkempt. Often, Bolbitis or Microsorum ferns, as well as Anubias, are planted here as well. Over time, all these plants grow, intertwining with each other, presenting an amazing picture, a true work of art, practically without any care or human intervention.

When creating a driftwood piece, keep a couple of nuances in mind: first, you should lay the moss on the substrate surface very thinly, literally branch to branch, avoiding dense clumps. Second, it needs to be tied tightly to the driftwood surface, without significant gaps. When tying, you can use a thin fishing line, which can be removed after a while, or you can use a cotton thread, which does not require removal as it rots away within a few weeks. And if something needs to be changed in the aquarium, the Java moss is moved along with its base. For example, it perfectly decorates flat ceramic pots with low-growing plants or epiphytic cultures attached to tree trunks. A plant that is not disturbed for a long time forms very beautiful thickets.

Another application of Java moss is decorating the back walls of the aquarium. For this purpose, a coarse-meshed net made of thin fishing line is attached to the back wall of the aquarium, into which the moss is pushed. Anubias and ferns can also be planted here. After a while, such a wall looks very beautiful and natural. Similarly, clearings, or rather carpets for decorating the bottom, are made. Moss is laid out between two layers of fine mesh and the edges are sewn with fishing line.

If you place a piece of moss in a permanent place and do not disturb it for several months, it will be clearly visible that the development of the stems proceeds differently. Initially, the stems reach out to the sides and down, enclosing the substrate and ensuring reliable attachment to its surface. Then, having firmly anchored, the plant begins to form numerous shoots directed horizontally and slightly upwards, so that the entire mass of moss takes the form of multiple layers arranged in arches relative to each other. Finally, probably after gaining enough biomass, shoots of the third type appear, directed vertically upwards.

The only thing to fear is the infestation of the plant’s stems and leaves by primitive algae. If algae grow heavily on the delicate leaves of Vesicularia, the piece of moss with parasitic algae should be removed; otherwise, the primitive algae can destroy the entire moss bush. In addition, Java moss in the aquarium can become a “collector” of dirt, but it can be easily “washed”. If the moss is not rinsed from suspended dirt, the dirt clogs the small pores of the moss leaves, and the plant simply suffocates without gas exchange in the leaves.

In an aquarium where direct water aeration from a compressor is arranged or there are a large number of large or substrate-digging fish, a significant amount of suspended particles appears in the water, settling on the moss threads. The plant looks dusty and unattractive, and its nutrition is disrupted. Algal fouling appears on the branches, which also does not improve the condition of the plant. Unfortunately, even intensive water filtration does not help preserve the decorative qualities of the plant. That is, Java moss is best grown in aquariums with a small number of fish and a relatively slow water current. It is periodically removed and washed with water.

In many decorative amateur aquariums, frequent spontaneous spawnings of various fish occur, predominantly Characins and Cyprinids, as well as rainbowfish. And for the fry of livebearing fish, Java moss thickets are simply paradise. Usually, they only bring joy to lovers of eating other people’s caviar. However, in the presence of extensive Java moss thickets in the aquarium, some of the eggs remain uneaten and develop into fry, which, in turn, also find shelter and food in the dense tangles of moss.

A very favorable biological environment is formed in these thickets, with very good oxygen saturation and rich in various microorganisms, primarily infusoria, which serve as the first food for the fry. It should not grow uncontrolled, because every small sprout trapped between plants forms a “felt” that disrupts water circulation. It dies when fish are treated with trypaflavine.

«6» Java moss reproduces very easily vegetatively. Propagation is carried out by separating overgrown parts from the bush, but one should try to traumatize the bush as little as possible. It is enough to place the smallest piece of moss into the aquarium to get a new plant. It is not necessary to press it to the base, as it sinks under its own weight.